As I was getting ready for dry hop addition ( my first time trying ) and I decided to take a gravity reading so I knew where I was at after 9 days fermenting. The fermentation was very vigorous and it is still very slowly going.

Here is where my problem is, I took a reading and it came out to 1.033 after 9 days and I really thought it was going to be lower than that. Should I rack to secondary and add more yeast or just let it be?

No no no no......never move a brew in the middle of fermentation! If you still got activity let it ride and don't rack to secondary vessel till gravity is stable and no fermentation activity present. Be patient and let the yeast do their job. There is still a lot of misconception about secondary fermentation vs. secondary vessel. Your secondary vessel is a bright tank or clearing vessel, shouldn't be any ferm going on in secondary unless you add adjuncts such as fruit or something. I'll actually even add fruit to primary and let it ferment out before racking since its also less cleanup